Cook the vegetables: Heat the oil in a stovetop pressure cooker over medium high heat (or in an electric pressure cooker on the sauté setting). Cook the onion, garlic and pork belly for 2 minutes, stirring often. Add the remaining vegetables and cook for 1 minute. Stir in the tomato paste, Italian seasoning, paprika, cumin and black pepper and cook for 1 minute again.
Pressure-cook the soup: Add all remaining ingredients to the pressure cooker. Close the lid and let the cooker to come to high pressure. Cook the soup for 10 minutes (12 minutes in an electric pressure cooker).
Blend part of the soup: Quick release the pressure and allow the soup to cool for 5 minutes. Remove about 1 cup of liquid and 1 cup of lentils/veggies and blend until smooth. Stir back into the soup.
Check for seasoning: Check the soup for seasoning and add a little salt and/or a dash of lemon juice if you feel like it needs a lift.